U.S. Pat. No. 3,915,921 discloses copolymers of unsaturated carboxylic acid monomers with an alkyl acrylate ester wherein the alkyl group contains about 10 to 30 carbon atoms that are efficient water thickeners.
Improved copolymers of about 40 to 87 weight percent of unsaturated copolymerizable carboxylic acid monomers, about 3 to about 20 weight percent of at least one alkyl acrylate ester wherein the alkyl group contains 10 to 30 carbon atoms and about 5 to 30 weight percent of at least one alkyl acrylate ester wherein the alkyl group contains 1 to 9 carbon atoms, optionally with a small amount of a comonomer cross-linking agent, rapidly absorb and retain large quantities of water and also absorb and retain ionic aqueous fluids. For use in many disposable nonwoven articles where such absorbents are useful these materials are preferably in film or fiber form. Because of the high Tg of these polymeric materials, it is difficult to extrude them in fiber or film form. Further, films pressed from the powders require high temperatures, the films are brittle and fragile, and have a reduced initial rate of water absorption.
Polymeric coatings for treating filamentary materials of a hydrophobic nature so as to give them a durable, antistatic, antisoilable finish are disclosed in U.S. Pat. No. 3,236,685; by a process including first coating the article with a polymeric polybasic acid and the coating dried, and then applying an epoxide or polyol to provide a hydrophilic insoluble coating having antistatic and antisoiling properties after heating to obtain cross-linking. The polyepoxides contain two or more epoxy groups and should have an epoxy equivalent weight below 1000. Epoxidized triglycerides and the epoxy polyethers of polyhydric phenols are typical. Typical polyols include pentaerythritol, trimethylol propane, sorbitol, glycerine, poly(oxyalkylene) glycols and the like. U.S. Pat. No. 2,838,42l discloses an adhesive which is a blend of a polyvinyl carboxylic acid and a compatible hydroxy polyalkylene compound as polyethylene glycol of molecular weight from 400 to 1,000, used in amounts of 140 to 160 weight parts per 100 weight parts of polyacrylic acid or 2-ethyl-1,3-hexanediol in amounts of 200 parts per 100 parts of polyacrylic acids. These compositions preferably include a cross-linking compound which is a polyfunctional epoxy compound reaction product of bisphenol A and epichlorohydrin. Textile sizes comprising a partially neutralized polyacrylic acid are disclosed in U.S. Pat. No. 2,702,796. These compositions require polymethacrylic acid, a plasticizer and a lubricating compound. The neutralization cannot be complete and preferably is carried out above a pH of 6 with, for example, sodium hydroxide, trisodium phosphate, morpholine, and the like. The plasticizers include ethylene glycol, glycerol, or sorbitol which is preferred because of its superior properties. The fourth required component is an emulsifiable lubricant, a polyoxyethylene condensate of a lyophilic aliphatic organic compound containing at least three oxyethylene groups as a hydrophilic portion and one or more hydrocarbon radicals forming the lipophilic portion and containing 12 to 18 carbon atoms. The patent teaches that for best results, a high melting wax is required such as bees wax, carnauba wax, and the like.